Rotary drier



Jan. 8, 1935. IM MADSEN ROTARY DRIER Original Filed April 50, 1928 \h. Nb @Tm vw n@ n. W.U`\v\\\\ mm. QN l. QN QN Guin mw. A NQ E11 V WN W Y my um mmf Patented Jan. 8, 1935 UNITED STATES PATENT OFFICE 273,876. Divided and this 21, 1930, Serial N0. 490,195

application October s claim. (ci. 347-3) 'This application is a division of my copending l application entitled. Portable asphalt mixing plant, Serial No. 273,876, iiled April 30, 1928, and which, issued on December 15, 1931 into Patent 5 No. 1,836,261. The invention which forms thesubject-matter of this divisional application is a rotary drier and is intended to dry, or otherwise heat-treat, broken or granular material which may be passed therethrough.' The rotary drier of the invention may, if desired, be equipped with a novel screen arrangement which constitutes a part of my invention, and may then be used for drying and also for grading the materials. a

The object of the present invention isto provide an efficient apparatus of this character which is of simple construction` and which is of compact arrangement, which renders it suitable for portable use.

Other objects which are inherent in the invention and which reside in the details of construction thereof will be made evident in the detailedl description of my invention.

My invention in its broad concept includes a drum or treating chamber through which the material to be treated is fed. `This drum or treating chamber is preferably rotatable and arranged to be rotated. Extending into one end of the drum is a fire-box or nre-tube which provides this end of the drum with a passage, which passage is formed between the wall of the drum and the fire-box. There is a means for supplying hot gases of products of combustion to the nre-box, which products of combustion or hot gases thereafter pass through the drum. The important advantage accruing fronr this broad concept of my invention is that the material to be heat-treated is caused to pass through a relatively hot area immediately before it passes from the drum, and is therefore eiiciently heat-treated. By locating the fire-box so that it projects into one end of the drum, the heat radiated by the nre-box as wellv as the heat which is carried by convection through the drum is used for heat-treating the material.

In the preferred form of device which includes the broad features of my invention just mentioned, the iire-box1 as well as the drum is of cylindrical cross-section, and the fire-box is of less diameter than the drum in order that the pasisage formed by the fire-box may be an annular passage. This is advisable in order that the feeding of the material from the drum may be continuous as Vthe-drum is rotated.

l The nre-box may be stationary and thedrum may rotate independently thereof, orA the firebox may be secured to the'drum and be rotatable therewith. Although it -is not essential tothe invention in its broad aspect, I prefer to have the fire-box rotatable with the drum morder that tvscreening means.

the nre-box may be used to support a bearing which constitutes a part of the means for rotatably supporting the drum. By this arrangement it is possible to place the support means for the drum on the outside of the apparatus, which is a,

much simpler construction than would be required if thel support means were required to beplaced on the inside thereof.

Another feature of the invention which may be optionally incorporated with the broad concept previously mentioned is the provision of a housing around the drum. This housing is provided for reasons of heat economy. The outer end of the nre-box projects to the exterior of the housing and the means for rotatably supporting the drum cooperates with this extending end of the fire-box. By -this construction the support means may be located at the exterior of the apparatus where it may be conveniently reached and where it is not subjected to the high heat which exists within the housing.

If the structure pointed out in the above paragraph is used on a material which is to be graded, the apparatus may have incorporated therewith a My invention provides a screening means which is oi annular construction and of larger diameter than the drum so that it may be disposed around the drum. 'I'he screening means is partly supported by the ilre-box'and has a closed end, the closed end being secured to the .fire-box. By this arrangement just dcribed it is possible to place the screening means around the end of the drier, as previously mentioned, which, is a compact arrangement and which maintains the material passing through the apparatus quite near to the source of heat. If desired,

the material may be deposited in bins included wit-.nin the housing, and this material win b kept warm for a long period of time due to the fact that it is not conveyed to separate storage bins and contacted with the atmosphere.

If desired, the screen arrangement of my invention may be used independent oi the nre box arrangement. When such screen arrangement is used independent of the other features oi' my invention, the screening means is placed around the outlet end of the rotary drum, anda means is extended inwardly beyond the end of the drum so that material passing through the outlet of the drum is guided into the screening means..

In the accompanying drawing I have illustrated an apparatus which embodies not only the broad.

concept of my invention, but also the various additional features which have just been pointed out. It should be understood in illustrating a device including all of the various features of my invention and -features of construction, that I do not intend to be limitedto the completefcom- A bination butintend my invention to'be considered" l as including the essentialand fundamental features by themselves as well as in combination with the other features mentioned which may be optionally employed.

Referring to the drawing in detail,-

Fig. 1 is a longitudinal section.

Figs.`2 and 3 are cross-sections taken on the corresponding lines of Fig. 1.v

Fig. 4 is a fragmentary cross-sectional view taken on the line 4-4 of Fig. 1.

'Referring to the drawing in detail, I will describe the embodiment of my invention disclosed thereby. The numeral 11 represents an inclined drier tube or drum through which the material to be heat-treated is" passed. 'nie inlet for the drumisprovidedbyanopeningwithinaninturned flange 14 secured to the right end of the drum 11.1 The means for supplying the material tothe drum is provided in the form of a chute 18. Spiral or helical blades 18 are provided near the inletendofthe drum 11 forcarryingthematerial .to be treated in a forward direction, and longitudinal agitating members 17 are secured to the interior of the drum near the central part thereof. Extendedintotheleftendofthedrum 11 isa v neem tube er nre-box 2o which is ei' cylindrical cross-section and is smaller in diameter than the drum 11 in order to provide an annular outlet passage 21. The nre-box 2Q consists of a metal shell 28 and a lining 24 of` refractory material. The nre-box 20 is preferably rigidly secured to the drum by suitable spider members 24a shown best in Pigs. 1 and 2. One part of the fire-boxv 20 projects from the end of the drum 11. as shown.

surrounding this outlet portion of the drum 11 is a screening means designated in general by the numeral 27. The screening means includes inner screens 28 and an outer screenl 29. The

-screens 28 and 29 are frusta-conical in shape,

being smaller at their left ends. Secured to the nre-box 20 a distance from the end of the drum 11' is an end plate' or annular disc 80 which extends radially outw'ard andhas theleft endsl of one of the screem 28 and the screenl29 secured thereto by suitable attaching angles 82. The end plate 80 serves'as a support forthe left ends of the screensandalsoservesasaclosuremeansto Aprevent material passing from the annular outlet 21- from escaping withoutbeing 4subjected to a screening action. The right end of the screen 29 and the adjacent ends of the two screens 28 are supported in a concentric position around the drum 11 by means of a tube or compound spider construction 88 which is secured to these ends of thescreensandalsotothedrumll. Theright end of the right screen 28 is supported in concentric position around the drum 1l by means of a supporting spider 34 secured to this screen andalsotothedrum. I'hescreensaremade frusto-ccnlcal in order that the lowermost portions thereof incline slightly to the left and decline slightly to the right in order that there will be a slight gravitational feed of the material which will carry it along the screen and be prop- 'erly subjected to a screening action.

, surrounding the drum l1 isahousing 38 which 'has a cylindrical portion 89 which surrounds the arrows 7l. `It will be noted that the hot .pace inte bine is wie inclusive. 'me extrem leftendofthefire-box 20extends`throughan annularopening intoanendwall81oftheho in diameter than the external diameter of fire-box 20 in order-that there will be but a minimum of heat lost Avat this point. Supported axial alignment with the fire-box and adj vtheencithereofisaburner82whichissupplied with fuel through a pipe 83. lhe burner 82 provides a jet of combustible gas 84 which islgnited and produces a name in the dre-box 20. To prevent a harmful interference with the jet 84 there is provided a flame shield84a which is located between the burner and the end of the fire-box and which is concentric to the axis thereof. The parts just mentioned constitute the means for delivering Ithe products of combustion or hot gases to the nre-box.

The drum ll is rotatably supported at its right end by means of a bearing 88 supported on suitable framework 88. Extended through the bearing 88 is a shaft 87.' the inner end of which supports a spider 88 to which the right end of thedrum is secured. Theouter end of theahaft u' 87 is provided with a gear 88 by means of which it is rotated. The left end of the drum is supported by means of a bearing ring 8l which is concentricallysecured on the end of the nre-box which projects outward through the opening 80.l

of the housing 88. A pair'of rollers 82,'one of able framework 84. y

Whenltisdesiredtoheat-treatamaterialby the apparatus shown, the burner is set into operation and products of combustion or hqt gases' are `passed through the drum in ti dicated by the arrows 70, these ing upward through the dus,

11 by means ofthe chute 18. this material paasing therethrough'in a direction indicated bythe and brought into intimate contact with the hot gases that pass through the drum. The agitating member terminates to the left of the right end of the annular outlet 21. Consequently. the

material which is being treated tends to lie onv the bottom of the drum at this point,and by reason of the fact that the drum is, slightly inclined, as shown, will travel to the left and through the annular outlet 21. Whenthe mate-y rial passes into this annular outlet 21, itis brought -into an area of very high temperature and any remaining moisture will be removed therefrom.

Itwillbeseenthatbyextendingtheiire-box into the end of thedrum il and by providing the outlet around the lire-box, the heat of radiation is utilised tomalntain the annular outlet" 21 at a very high temperature.

As the material passes fromrthe end of the vdrum 11, it falls into the space within the screening means 27. Since the screening means rotatcs with the drum, the material is agitated, and

since the lowermost part of the screening means um ieri screen sa win :anim um. screen 29. the end of the anun u and providing an outlet Any material whichis small enough to pass ,through the screen 29 will fail-into the bin 43,

and any material which lfalls ontov the' screen .29 but vis'to large to pass-therethrough, will travelalong-the screen 29 and i'all from the end thereofintofth'efbinz, asjindicated. The materiall which .large-to. pass through the left screen 28 tothe right 4and over -the right screen 28. .The right screen is coarser-'than the left screen 28 and ofthe material therethrough and intovthe bin 45.1" The large material which does not pass through either of the screens 281passestromythe endo! the right screen28into-thebin 46.1

. v The nrst vimportantjieature'"of inventiong is the extending of the' heater, tube or tire-box 'tends to'travel therethrough by gravity. said means being attached to and rotatable 20 into the end of the drum -ilandioririingtthe outlet between the nre-box and thew'all oiy the drum. It is of course. preferable to have the parts concentric and to have; the annular voutlet 21 completely annular'in order that the material mayfpa'ss--i'rom the drum at all rotational vposi- 20. Various other means could be provided tions -of.-.thefdrum. It the material does not need-to be screened,'the screening means shown may be eliminated. and i! thexnaterial does not have vtobekenty heated. `the lhousing and-bins mw be' and l lsuitable @We vrovided at'the'- outlet-endet tlief` uoned in; the, tion. I preierl that the outer end 'of the e support m ."ind; support means'l may be vonthe'exteriorv apparatus.'l This isvnot essentialglioweve and if desired the ilre-boxmay be stationary andthe support means may be a'ssociatedfwith' the left end of. the drum 11 by providing a bearing ringthereon, andbyproviding suitable sup'- porting rollers such as the rollers 62. Ii! this v arrangement wereprovided the. drum would rotate around the inner'exid of theme-50x20. The burner 52 'and shield are 4typical of any typeo! hot gas supply means which are suitable to supply hot gases to the nre-bg!! out-departing fromfthe-invention.

When it is desired to screenv the material. the

screening means ot my invention may be utilised.;v

The screeningmeans is placed around the left 'l end oi.' the 11 in order'to economise on space. It the screening means were placed adjacent tofthe not around it; the appa- -would ratus would ibesomewhat longer and 5' immane pum by me iiii-tjiiiii-g.,` has secured thereto the end plate 30 'v vliieh"suiv-'-A ports the lefti'of screening vand a rightward direction' along screens` v28 l and 29. 'me bins 4s to 4o inclusive included inthe housing 38 heated. jI

For convenience! have in order that they n iay bekent l villustrated different .partsvoi' the invention as being of conventional construction; lll'or example. the drum 11 is proivided'with conventional agitating members and .to provideja stiittior'iary drumfll with feeding j means therein, such a structure comes vwithin the scope oi' my inventioni provided it utilises the feature ot the tube-cr nre-box 20 extending into ".nationl of:

'exteriorlyfth'ereo said fire-box providingean annular outlet in the end of said drum around said nre-boxpanda screening means around the end of, said druinzsnd so inclined that said material screening with said tire-box.

2.Inadrierottheclassdescribed.theoombination of: a drum through which the materialtobetreated ispassedinonedirection; a tire-box extending into one end of said drum and partially supported exteriorly thereof, said firebox providing an annular outlet in the end ot said drum around said fire-box; and a screening means around the end o! said drum and so inclined that said material tends to travel therethrough by gravity in a direction opposite to the travel of said material through said drum. said Hscreening means being attached to and rotatable witnisaid tire-box.

an imperforate rotatable drum lthrough which material to be treated is passed; a re`box extending into said drum and providing an annular outlet at one end thereof; screening means of larger diameter than said drum and surrounding said drum at said outlet end of said drum; and support means whereby said screen- -ing means is supported by said iire box.

4. In a drier of the class described, the combination of: a rotatable drum through which materlal to be treated is passed: a iire box extendinginto saiddrumand providing an annular outlet at one end thereof; screening means of larger diameter than said drum and surrounding said-drum at said outlet end thereof, said screening means projecting beyond the end of said drum: and support means extending inwardiy. from. said projecting end of said screening tofsaid-nre box.

5.@In ardrier ot the class described, the combination of: an imperiorate rotatable drum `through which material to be is passed. o' said an outlet at one end thereof; a member extending into the outlet lend ot said thus forming an annular outlet passage;

means surrounding said drum and extending beyond the end o! said drum; and means extending inwardly from said screening means to said member whereby said material is directed 13. In =a `drier of the class described, the combifrom said annular outlet into said screening r means.

6. In a drier ot the class described, the combination of an imperiorate rotatable drum through which material to be treated is passed, said drum having an outlet at one end thereof; screening means surrounding said drum and extending beyond the end of said drum; and means extending inwardly beyond the outlet end of said drum, whereby said material, is directed from said outlet into said screening means.

MARTIN MADBEN. 

